Frangible port closure



May 8, 1951 H. c. OTIS ET AL FRANGIBLE PORT CLOSURE Filed June 11, 1945 Herbert G 0:18

Huber: C Z and IN V EN TORS Patented May 8, 1951 UN ITED- STATES PATENT ()FFICE FRANGIBLE PORT CLOSUREv Herbert G. Otis and Hubert C..Laird,.-Dallas, .Tex., assignors to Otis Engineering Corporation, Dallas, Tex, a corporation of Texas Application June 11,1945; Serial No. 598,890

6 Claims. 1

This invention, relates to new and useful improvements in port closures.

It is one object. of the invention to provide a closed port inya conductor or vessel, which port is, adapted to be opened by means of fluid pressure-from within the conductor or vessel.

An important object of the invention is to providea port closure which is initially closed to prevent ,fiow of ,fluids therethrough in either direction and wherein the meansfor closing the port will resist-opening thereof until a predetermined fluid pressure differential is applied across the port to open it.

A further object ofthe invention is to provide a port closure, of the character described, wherein-the closure means for the port is designed to withstand substantially as great a pressure from without the conductor as the conductor itself will withstand, whereby the normal use and functioning of the conductor is not affected or decreased by -the provision of the port and closure 'device therein.

Still another object of the invention is to provide a fluid port having a plug secured therein to prevent flow through .said port in either direction, said plug being displaceable completely from the port by application of a predetermined fiuid'pressure, and when displaced affording full unobstructed opening of the port.

A still further object of the invention is to provide a port closure of the character described which does not extend into the bore of the conductor in which it is mounted.

It is a particular object of the invention to provide a port closure which is arranged to withstand a fluidpressure from without the conductor in which the port is located as great as the pressure which the conductor will withstand, and which may be displaced outwardly from the port by substantially smaller fluid pressure from within the conductor.

Another object of the invention is to provide a port closure, of the character described, which is readily interchangeable in the port in the conductor, whereby plugs may be renewed or interchanged to meet varying conditions in the use of the conductor.

Additional objects and advantages of the invention will be apparent from a reading of the following description of a device constructed in accordance with the invention, and reference to the accompanying drawings, wherein:

a Figure 1 is a View partly in elevation and partly in section, ofa device constructed in accordance with the invention and showing the same installed in a conductor,

FigureZ is acontinuation of Figure 1 illustrating a. transverse vertical sectional view of a removable plug or plunger which may be used in the conductor in combination with the port :closure,

Figure 3 is afragmentary view showing an end elevation of the port closure,

Figure 4 is a fragmentary transverse vertical sectional viewof a modified form of. closure plug for the port,

Figure 5 isa. fragmentary transverse vertical sectional view. of another form of closure plug for the port,

Figure 6 is a similarview showing another mannerof mounting the closure plug in the port, and

Figure --7 is a fragmentary transverse vertical sectional viewofamodifiedforin of closureplug and port.

In the-drawings, the numeral Ii] designates a tubular housing having an axial bore ll. Internal screw .threads .l2 are provided at each. end of the .bore of thelhousing, whereby the housing may be connected in a iiow conductor T. The boreof thehousing is substantially the same as the bore of the conductor so as toprovidea sub,- stantially unrestricted flow passage therethrough;

Asis clearly illustrated in Figure 1, the housing .is provided with a central external annular flange, l3. A lateral opening-or. port 14 is formed in the mid-portion ofthe flange [3, and the outer portion l5 of the port is enlarged iii-diameter andprovided with internal screw threads, whereby an outwardly facing'annular shoulder 15 is formed at the inner portion of the port.

A closure assembly C is mounted within the port The closure assembly includes a bushing I! which is provided with external screwthreads and adapted .-to be threaded into the enlarged outer portion -I5of the-port. The bushing is providedwith anaxialbore which is reduced in diameter at its inner end [8 so that an outwardly facing annular tapered stop or seat I9 is formed in the bushing near its innerend. A short distance beyond the seat !9,.the bore of the bushingis. enlarged to form'a shoulder 20,-and the bore beyond this shoulder is provided with internalnscrew threads 2|, A closure member or plug, .22, having its inner portionbevelled to conform-to the-seat I9, is positioned within the bushing to close the bore thereof, and thereby close. the port 14; A shear plate or disc 23 having a diameter greater than that of the plug 22 is securely confined between a follower ring 24,

of the same-diameter as the plug-,and the'outer end of the plug, the assembly being held together by means of a screw 25 which extends through the ring and disc and into a threaded recess in the center of the plug.

The plug is held tightly within the bushing I! by means of a clampin sleeve 26 which is provided with external screw threads and adapted to be threaded into the enlarged bore 2| of the bushing to engage the annular shear disc 23 which projects beyond the periphery of the plug into the enlarged portion of the bore of the bushing, so that the disc is clamped securely between the shoulder 20 and the inner end of the clamp-' ing sleeve.

It will be noted that, when the closure assembly is in place, the plug engages and is held securely against the seat I!) and the disc 23 .is securely clamped in sealing relationship between the shoulder 29 and the clamping sleeve 26.

Obviously, any pressure fluid acting upon the plug assembly from the exterior of the housing will only serve to urge the plug more tightly against the seat 19, and thus displacement of the plug inwardly of the port is prevented. Since the disc 23 is clamped securely between the shoulder 20 and the clamping sleeve 26, displace ment of the plug outwardly from the port is initially prevented. However, by the application of a suificient pressure differential from within the housing, the plug may be forced outwardly from the port to permit flow of fluid therethrough. The fluid pressure will move the plug outwardly of the bore of the clamping sleeve and will thus shear off that portion of the shear disc 23 extending beyond the external diameter of the plug to permit the plug to be completely displaced from the bushing and sleeve. By varying the thickness of the shear disc, it will be seen that the pressure difierential required to be exerted across the plug to displace the plug may be controlled and predetermined. Therefore, the plug may be so secured within the port as to be displaceable at various predetermined pressure diiier'entials. Also, in some instances it may be very desirable to make the plu from a high shear strength material and to make the shear disc of low shear strength material such as lead or copper. In this manner, the shear disc may be made thicker and more accurate control of its shear strength obtained than if it were made of a very thin piece of higher shear'strength material; I Since the thickness of the plug and the length of the small bore 18 of the bushing are each made substantially equal to the wall thickness of the flow conductor T, it is obvious that the device will withstand substantially as great an externally applied fluid pressure as will the conductor itself, since either the large portion of the plug, or the length of the reduced portion of the bushing, must be sheared to permit inward displacement of the plug to the port. Thus, the device may be used in conductors wherein there are high pressures exteriorly of the conductor without decreasing the strength thereof or interfering with the normal operation of-the cond-uctor.

Since the thickness of the shear disc is substantially less than the thickness of the entire plug, it will readily be seen that the entire thickness of the plug prevents the plug from being displaced inwardly by the fluid pressure, while only the very much smaller thickness of the shear disc prevents displacement of the plug outwardly from the bushing. Or, the plug may be made of high shear strength material while the shear disc may be made of a relatively low shear strength material. Therefore, the shear disc may be sheared from the plug assembly by relatively small pressure differentials to permit the plug to be displaced outwardly from the bore of the bushing and the sleeve.

When it is desired to open the port, it is only necessary to provide some means for closing the bore of the conductor beyond the port and to apply fluid pressure within the conductor to displace the plug from the bushing. Such a closure means is illustrated in Figure 2.

A coupling member 30, having a bore 3! which is reduced at its mid-portion to provide an annularseat or shoulder 32 therein, is connected in the flow conductor T beyond the housing ID by means of screw threads 33 formed at each end of its bore. The reduced diameter of the seat 32, which is slightly less than the diameter of the bore of the conductor, does not materially interfere with the normal operation or the flow of fluid through the conductor. When it is desired to open the port, a removable plunger 34 is inserted in the flow conductor to seat upon the shoulder 32 in the coupling member, whereupon said plunger closes off the bore of the conductor to prevent flow therethrough past said coupling member. Thus, fluid may be pumped into the conductor to build up a fluid pressure therein which will readily displace the plug 22 from the bushing i1 and permit flow of fluid outwardly through the port.

The plunger may be of any desired type, such as a large ball, but is illustrated as having a body 35 with an annular bevelled seat 36 at its lower end. The diameter of the plunger body is reduced above the seat and a cup-shaped packing ring 3i is mounted on this reduced portion, being held thereon by a spacer thimble 38 and a retaining nut 39. The upper portion of the plunger body is still further reduced in diameter to form a retrieving connection 40, whereby the plunger may be engaged and removed from the conductor, if desired, by means of a suitable retrieving tool (not shown).

The engagement of the plunger with the shoulder 32 in the coupling member may of itself provide ample closure of the bore of the conductor to permit application of a pressure fluid differential sufiicient to displace the plug 22 from the port in the housing. However, if such is not the case, the cup-shaped packing 31 will engage the wall of the conductor to seal off around the plunger and prevent all fluid leakage past said plunger.

Manifestly, more than one of the port closures may be provided in the same flow conductor, whereby the ports may be opened at difierent positions in the bore of the conductor. It may also be desirable, when more than one of the devices are connected in the same conductor, to provide for opening the different devices at different pressure diiferentials. This may be done by providing the plugs with shear discs of different thicknesses or of difierent shear strength materials, as has already been explained.

It is readily apparent that the closure assemblies may be secured in the port of the housing in various suitable manners. Also, the shear element on the plug may difi'er from that already described. In Figures 4 through 7, we have illustrated modifications of the invention differing from that form just described.

In Figure 4, the shear disc is shown as made integral With-the-plugw- Otherwise, theclcsure assembly is identical with the -form--previously described. A- pIug'SIl-is provided with anexternalannular flange 5t formed integral-with its outer end, and this flange is held securely in placeagainst the shoulder by the clamping sleeve Since the flange is of substantially less thickness-than the thickness ofthe-entire plug-, it will readily be seen that, while the entire thickness of the plug prevents inward displaces ment'thereofby-fluid press-u-i-e; only the very much smaller thickness of the flange 5i prevents displacement of the -pl-u'g outwardlybya fluid pressure difierential from within the conductor. Therefore, the fiange may be -sheared =from=the plug by a relatively small pressuredlfferential to permit the plug to 'be displaced outwardly iromthe bore of the bushing andthe-sleeve.

Ifdesired; the sheardisc may be formedof a very softmetal, such as lead, to provide for ready displacement of the plug at low pressures. A structure which is adapted for the use. Of SllC'h a-discris illustrated in Figure 5. A plug 55 seats within the bore of a bushing 56; which is threaded into the port-tothe=bore l5 of the portnin-the same manneras has been previously described. However, in thisform; the bushing is provided with a bore whichis substantially the same or only slightly-larger than the external diameter of the plug. An enlarged annular groove 5? is formed in the boreofthe bushing justbeyond the outerendofwthe. plug and-.a suitable metal may belpoured, pressed, cast or otherwise placed, in this-annular groove toforina shear disc .58 at the rear: of the plug. Itmwill'readil-y be seen that the thickness of the-plugand the. disc pre-v vent displacement. of.:the plug inwardly .of the port, but: that. pressure fromwithin thelhousing will force the. plug outwardly of. the; housing..;t.o shear the discuss and permitcomplete displace: ment of the plug from the bore of thebusfins.

Obviously, therbushing I'i, illustrated in Figures 1 and/1, may .be. omitted if desired. Such a structure is illustrated in Figure 6, wherein the plug and...clamping-sleeve are. mounted directly in,,the. port formed'in the housing The inner portion of the port is reduced in .di,- am er whereby. an. annularftan .seat BI i formed near the inner end of the port. A short distancebeyond the seat i,.-the bore of thetport is' enlarged. toform a shouldcr152, andthebore beyond the shoulder provided; with internal screw threads 63.... A closure member. or. blue 22,. identical with that. of the. form first described, isppositioned. within the. port-to, close. the bor thereof, andis. held securely-inlplace intheport by means; or a .c1amping.s1eeve :2 6, which .is provide wi h; xter al..scr,ew threads and. adanted to be threadedintothethreaded portion 63 of the port. The shear disc 231's securely clamped betweenthe shoulder SZ-Mandthe inner 81161 01". the clamping. sleeve. in the samemannerc-asi was the disc of the form first described.

In this form of the invention, we have merely omitted the bushing I! and mounted the plug, shear disc and clamping sleeve directly in the housing port. The operation of this form of the port closure is the same as that of the form first described.

In the port and closure illustrated in Figure '7, the housing or body Ill is provided with a port 65 having its inner portion (it reduced to form an internal annular shoulder 61. The large outer portion of the port is provided with screw threads and is adapted to receive a tubular clamping sleeve 68 for securely holding a plug 6? 59 in place the port againstthe shoulder 61; The plug is in the shape of a .flat- -.diso.having an annular groove ill formed in its outer surf-ace. It is to be noted that the grooveis largerain internal diameter than the reduced inner .por-. tion- 65- of theuport whereby the total thickness of the plug overlies the marginal-said reduced portion and thetotal shear strength of the plug resists inward displacement with respect tdthe body). Thegroove it. provides s weakened shear section of lessen strength than that. of the remainder ofthe plug, and the .plug mayqbe displaced outwardly with respect 130413118. body. and porthya predetermined .lowerlpr-essure from withinthe housing. The amountlof rmaterial remaining between the bottom or the groove.- and the inner surface 01' theplug. determinesythe shear. strength and pressure requiredto displace the plug outwardly.

Obviously, the-flange is may .be omitted. if desired and the housing may the provided-With a thickenedwall sectionin whichitheport may be. formed and; the closure positioned.

From the foregoing, it will readily beseenthat the. forms pf the invention illustrated in=Figu es 1, 4 and 5 provide-apart closureassembly h may be; removed interchangedf l." :Va-r k .,.S purposes, .such. as testing, if desired. 14 115. formsof. the invention-shown. in Fi res-.5 and 7,; the .clesure plug .;may be remo ed end/B changed. or replaced :if; ;desired ,;p ut he; ntire closure. ass mbly; may not be s parate y. ested out of the, housing.

It will also be seenthat we :have provided "a port :closure plug assembly whereinythe entire thicknessoflthe plug and. shear disc ,p-reven Ward displacement. of :the .p usafrom. the, ports, while, on1y,the.reducedthickness oi the shear sect-ion or; disc prevents; outward displa emen ofgthe plug; Therefore the plug ;will withstand as, great a pressure y hem :the. housinggas will the conductor, in; whichit is;.cQnnected.;.-wh- 1e1 a substantially lower pressure or pressure differentiail, wil'l:;disl 1alce ;the.;plus..,ou;twardly from the port.

It :Will alsobe seenthata plurality of thedevicesmay bev usedtoopen ports at yariousposi-v tions. within a conductor, and that the..yar:i0.u plugs or a single plug maybe set for any desired pressure differential to permit opening theport.

Theforegoing.description.of the invention is explanatory-.on1y,. and changes-gin. the details of the construction.illustratedunay bemade by those. skilled in the art within thescope of::the appended. claims, without departing,- from the spirit; or the; invention.

'What. Wecla-imrand desire to'secure by Letters Patent. is

A. portand closure apparatus. including, a tubular housing 'al-fiow conductor. andhaving allow port, extend.- ingthrough its wall;:saidportwhavingtthe outer portion of its bore enlarged to form an outadapted *to. be.; .connectedsWi-th having a bore slightly larger than-the diameter of the closure plug threadedly secured within the outer :enlarged portion of the port and engaging the shear element to clamp said annular projecting portion of the shear element against said outwardly facing annular shoulder to restrain outward displacement of the plug from the port, said shear member being frangible upon the application of a predetermined force against the plug from within the housing to permit the plug to be displaced from the port.

2. A port and closure apparatus of .the character set forth in claim 1, wherein the shear element is separate and releasably secured to the plug by means of a clamping washer and a clamping screw which extends through the washer and shear element and is threaded into the plug, whereby the shear element may be. removed and replaced.

3'. A port closure assembly including, a tubular bushing adapted to be mounted in a ported member and having one endportion of its bore reduced to form a sealing seat in said bore intermediate the ends thereof and also having the opposite end portion of its bore enlarged to provide a clamping shoulder therein spaced from thesealing seat, a solid closure plug arranged to fit in the bore of the bushing and to seat in sealing engagementuponthe sealing seat therein, ashear disc carried by the plug and projecting laterally peripherally therefrom and engaging against said clamping shoulder, and a tubular clamping sleeve threadedly mounted in the enlarged portion of the bore of the bushing and clamping the annular projecting portion ofthe shear disc against said shoulder to restrain outward displacement of the plug from the sealing seat, said shear disc being shearable upon the application of a predetermined pressure upon the sealing seat side ofthe closure plug-to permit the closure plug to be displaced from the sealing seat through the bore of the sleeve. 4.'A port closure assembly of the character set forth in claim 3, wherein the shear disc is separate and releasably secured to the plug by means of a clamping washer and a clamping screw which extends through said washer and shear disc and is threaded into the plug, whereby the shear disc may be removed and replaced on the plug.

5. A port and closure apparatus including, a walled body member having an opening extending through its wall, and a closure assembly for said opening including, a tubular bushing removably mounted in the opening and having the inner end portion of its bore reduced to form a sealing seat in said bore intermediate the ends thereof and also having the outer portion of its bore enlarged to form an outwardly facing clamping shoulder spaced outwardly from said sealing s'eat,a solid closure plug arranged to fit in the bore of the bushing and seat in sealing engagement on the annular sealing seat therein, a shear disc carried by the plug at its outer end and projecting annularly laterally therefrom so as to overlie and engage against the outwardly facing shoulder in the bore of the bushing, and a tubular clamping sleeve threadedly mounted in the enlarged outer portion of the bore of the bushing and engaging the annular projecting portion of the shear disc to tightly clamp said projecting poition of the disc against the clamping shoulder, said shear disc being shearable between the outer periphery of the closure plug and the inner periphery of the bore wall of the clamping sleeve upon the application of a predetermined pressure against the plug from within the body member to permit the plug to be displaced from the sealing seat through the bore of the sleeve.

.6. A port and closure apparatus including, a walled body member having an aperture formed in its wall, an outwardly facing seat formed in said aperture, a closure member arranged. to be mounted in the aperture for closingthe same, and means. for holding the closuremember in aperture closing position, ,said closure member being provided .witha thick high shear strength central section and a thin lower shear strength section surrounding said central section and disposed-between said central section and theholding means to resist outward displacement of the closure member from the aperture, the thick high shear strength central, section of the closure member engaging and seating upon the outwardly facing seat in the aperture to seal the same against inward fluid flow through the aperture, said lowerv shear strength section being shearable upon the application of a predetermined pressure against the inner sealing seat side of the closure member to permit the thick high shear strength section of the closure member to be displaced outwardly'of the aperture to open the same.

- HERBERT C. OTIS. HUBERT C. LAIRD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS FOREIGN :PATVENTS' Country Date Great Britain Oct. 12, 1939 Number Number 

